Children in the southeastern United States have been showing up at hospitals after encounters with what experts say are the most poisonous caterpillars in the country.

Known as the furry puss caterpillar, and looking something like a crawling shag carpet, it a tempting target for petting but the result can be excruciating pain from poisonous spines lurking in the creature's shaggy hairs, experts say.

The toxic spines have barbed ends that cause them to stick to the skin.

In addition to those attempting to touch the furry creatures, known scientifically as Megalopyge opercularis, some children have had the caterpillars fall on them from trees.

Reports of children being stung have come from North Carolina to Florida.

"A puss caterpillar sting feels like a bee sting, only worse," says entomologist Don Hall from the University of Florida. "The pain immediately and rapidly gets worse after being stung, and can even make your bones hurt."

Silena Lane of Boiling Spring Lakes in North Carolina, whose 4-year-old son was stung, confirms that.

"My son cried for two straight hours from the pain, so I hope no one else has an encounter with one," she told WECT-TV.

A sting by the caterpillar causes an instant reaction that feels similar to a bee or wasp sting, followed by redness and swelling that can spread from the sting location, experts say.

Pain from such a sting can last between 20 to 30 minutes, they say.

Hall recommends using cellophane tape on the areas of the sting, which when pulled away from the skin can remove spines from the sting site.

That can help decrease the pain, the level of which can depend on the location of the sting and the number of spines embedded in the skin, he says.

The furry puss caterpillars, so named for their resemblance to a cuddly house cat, can be found living in oak, elm and sycamore trees along the U.S. East Coast from Florida north to New Jersey.

Populations of the creatures tend to increase or decrease dramatically in response to weather and food availability and numbers seem to be showing an upsurge currently, which may account for the number of stinging incidents, says Hall, who has been on the receiving end of stings several times during his studies of the caterpillars.

The stinging spines aren't the only unique feature of the inch-long caterpillars; they're also known for flinging their own feces away from their bodies.

This odd poop-throwing behavior may be to prevent parasites from being attracted to the caterpillars, Hall suggests.